Boiler furnace



J. c. HOBBS BOILER FURNACE `lune 26, 1934.

Filed July 2, 1925 3 SheeLS-SheeI 1 e, HI 7 .77

IN VEN TOR.

June 26, 1934. .1. c. HOBBS vBOILER FURNACE Filed July 2, 1925 3Sheets-Sheet 2 /Nl/ENTR aAqC ATTORNEYS June 26, 1934. J, c, HOBS BOILERFURNACE Filed July 2, 1925 3 sheets-sheet '5 A TTORNEYS' Patented June26, 1934 UNITED sra-TES BOILER FURNACE James C. Hobbs, Panesville, Ohio`Application July 2, 1925, Serial No. 40,993

17 Claims.

My present invention relates to steam boiler furnaces, and particularlyarrangements by which the walls of such furnaces' may be maintained andalso particularly arrangements for connecting so-called slag screentubes tothe steam boiler.

My invention will be best understood from the following description andthe annexed drawings in which Fig. 1 is a side sectional elevation of anillustrative embodiment of my invention; Fig. 2 is an enlarged sectionon the line 2-2 of Fig. 1; Fig. 3 is a section on the line 3-3 of Fig.2; Fig. 4 is a rear elevation of a part of the arrangement shown in Fig.1; Figs. 5 and 6 are respectively a front elevation and a section on theline 6-6 0f Fig. 5, showing a connection shown in place in Fig. l, andFigs. 7 and 8 are respectively a longitudinal section `on the line 7-7of Fig. 8 and a plan view, each on an enlarged scale, of a steam andwater separator shown in place in Fig. 1.

Like reference characters indicate like parts throughout the drawings.

For the purpose of illustration, I have selected a water tube boiler ofa well-known form placed over a furnace arranged for burning powderedfuel. The boiler, as illustrated, has a transverse steam and water drum10, downtake headers 11, uptake headers 12 and water tubes 13. Thefurnace chamber 14, in the illustrative embodiment, is provided with anextension in front of the boiler. In the roof of such extension is apowdered fuel burner 15 arranged to direct the fuel downward. into thechamber 14. The front wall 16 is provided with air ducts and air supplyopen= ings into the furnace. The rear wall 17 is made up of one or moresections, each independently supported and arranged with slip jointsbetween them.

Across the lower part of the chamber 14 is a plurality of slag screentubes 18 connected at their front ends to headers 19, which, in turn,are connected through a pipe or pipes 2O and tubes 21 to the waterspaces of the drum 10. The slag screen tubes are inclined upwardly sothat their rear ends are higher than their front ends, these higher endsextending through the rear furnace wall.

In front of the rear wall 17 is a row of tubes 22 which extendpractically parallel with the inner face of the wall 17, the lower endsof the tubes 22 being bent outwardly and extending through the rearwall, there being a tube 22 for each of the tubes 18.

Each tube 22 is connected to a tube 18 by a connector 23, shown on alarge scale in Figs. 5

and 6, this connector being arranged with a removable closure 24 so thata cleaning tool may be inserted into the tube 18. If desired, theopening 24 may be made of such a size and in such a position, as shown,that a tool may also be entered in a tube 22. 'Ihe upper ends of thetubes 22 extend out through the rear wall 17 and are connected toinclined headers 25, the high ends of which are connected to verticalpipes 26 which, in turn, are provided with tubes 27 and 28, the formerof which enter the steam and water drum 10 above the normal water levelthereof and the lower row 28 entering at about the normal water level inthe drum 10. x

With the arrangement so far described, the tubes 18 are iilled withwater from the drum 10 through the tubes 21, the pipe 20 and the headers19. The tubes 18 serve to cool the lower part of the furnace to causethe slag to be thrown out in hardened particles and these tubes absorbheat so that the water therein rises through the connections 23, thetubes 22, the headers 25, the pipes 26 and the tubes 27, 28. Thecirculation of the water through the tubes 22 serves to maintain therear wall 17 by protecting it from the` to an upper header 33 outside ofthe furnace wall. At the ends of the headers 32, 33 are downcomers 34,35 and the lower header 32 is connected by the pipe 36 to the pipe 20,whereby the lower header 32 is supplied with water from the drum' 10.

The upper header 33 is connected by a pipe 37 to a header 38 which, inturn, is connected by pipes 39 to the steam space of the drum 10.Between the pipe 37, the header 33 and the downcomer 35, a steam andwater separator 40 may be provided, which may conveniently have the formshown best in Figs. 7 and 8, the interior of the separator beingprovided with helical spiral shelves 41 to separate the steam and waterreceived from theheader 33 to permit the steam ,to ow upward to the pipe37 and the water to be turned to the downcomer 35.

The straight vertical portions of the tubes 30 may be located inrelation to the Wall 31 either in front of the wall or partly in thewall and, in the arrangement which I have used for` purposes ofillustration, each of these straight portions is located in a slot 42 inthe refractory wall. The wall 31 is held in place by a plurality offixed vertical beams '43 between which extends a casing 44, a layer ofheat-insulating material 45 being interposed betweenthe refractoryabsorbed by the tubes 30 and the water will flow upwardly therein to theheader 33 and from thence through the downcomers 34, 35 to the lowerheader 32. In this way, a complete circulation of the water in the sidewall cooling tubes is obtained independent of the boiler circulation,the' amount of water passing from the pipe 20 through pipe 36 to thelower header 32 being equal to the amount of steam generated in thetubes 30 plus any Water which may pass through the pipe 37 to the steamspaces of the boiler.

If desired, theslots 42 may be permitted to be filled with slag and suchtubes maintain the wall not only by keeping its temperature low enoughto avoid the destruction of the wall, but' also will prevent the bulgingof the wall inwardly, since such tubes act as a kind of holding members,the outward motion of the wall being prevented by the beams 43.

If desired, the upper header 33 may be inclined somewhat so that thepipe 37 can be connected directly to it to receive the steam which wouldthen rise to the higher end of the header. While preferably I providethe downcomers 34, 35 at the ends of headers 32 and 33, it will beunderstood that such downcomers may be located in any desired position,so long as they are subjected to less heat than are the tubes 30. As hasbeen said, the lheader and downcomer arrangement provides a device bywhich there is a local circulation in the side wall cooling tubes, sothat small piping between the tubes and the boiler proper need beprovided instead of the large piping which is necessary if the side wallcooling tubes formed part of a direct circulatory connection between thewater space and the steam space of the boiler. It will also beunderstood that, if desired, the connection from the header 38 throughtubes 39 to the drum 10 may be beneath the -water level sothat the pipe37 will be lled with water at all times. The possibility of formingsteam pockets in the pipe 37 and its connections is avoided by causingit to carry steam only.

It will be understood that the arrangement which I have shown isillustrative only and that the embodiment of my invention may be widelyvaried. It will also be understood that some of the features may be usedindependently of others.

I claim:

1. In a steam boiler and its furnace, a bank of vertically disposedfurnace wall cooling tubes subjected to the heat of the furnace, anupper and a lower horizontal header connected to the ends of said tubes,downcomer pipes connecting said headers, a connection between the lowerheader and the boiler water space and a connection between the upperheader and the boiler steam space, and a steam and water separatorbetween said upper header and said last named connection.

2. In a steam boiler and its' furnace, a bank of vertically disposedfurnace wall cooling tubes subjected to the heat of the furnace, anupper and a lower 4horizontal header connected to the ends of saidtubes, downcomer connections outside the wall and connecting saidheaders, a connection between the lower header and the boiler waterspace and a connection between the upper header and the boiler steamspace.

3. In a steam boiler andits furnace, a bank of furnace lwall coolingtubes subjected .to the heat of the furnace, headers outside the furnacewall and connected to the ends of said tubes, a pipe `connection betweensaid headers outside `the furnace wall, a water connection between oneof said headers and the water space of said boiler, a steam connectionfrom the other header to the steam space of said boiler, and a steam andwater separator between said upperheader and said steam connection.

4. In a steam boiler and its furnace, a plurality of slag screen tubesextending across the furnace, a plurality of vertically disposed wallcooling tubes, connections between the upper ends of said cooling tubesand the boiler spaces, connections between one end of each of said slagscreen tubes and the boiler spaces, the lower end of each of said wallcooling tubes Abeing bent outward, and angle fittings, each connectingthe other end `of one of said slag screen tubes with the bent lower endlof one of said wall cooling tubes. -f

5. In a steam boiler and its furnace, a plurality of slag screen tubesAextending across the furnace, a plurality of vertically disposed wallcooling tubes inside the furnace wall, with their lower ends bentoutwardly and extending through the furnace wall, connections betweenthe upper ends of said cooling tubes and the boiler spaces, connectionsbetween one end of each of said slag screen tubes and the boiler spaces,and angle fittings outside the furnace wall, each connecting the otherend of one of said slag screen tubes with the lower end of one of saidwall cooling tubes. A

6. In a steam boiler and its furnace, a bank of vertically disposedfurnace wall cooling tubes, an upper and a lower horizontal headerconnected to the ends of said tubes, downcomer pipes connecting saidheaders, a connection between the lower header and the water spaces ofthe boiler, a connection between the upper header and the. steam spaceof the boiler, and a steam and water separator, between said upperheader and said last named connection.

7. In a steam boiler and its furnace, a bank of vertically disposedfurnace wall cooling tubes, an upper and a lower horizontal headerconnected to the ends of said tubes, downcomer pipes connecting saidheaders, a connection between the lower header and the water spaces ofthe boiler, and a connection between the upper header and the steamspace of the boiler, said last-named connection having a steam and waterseparator therein adjacent the upper header.

8. In a steam boiler and its furnace, a bank of vertically disposedfurnace wall cooling tubes subjected to the heat of the furnace, anupper and a lower horizontal header connected to the Vends of said tubesand outside the furnace wall, a

vertically disposed downcomer connection at each end of the upper headerand connected to the lower header, a connection between the lower headerand the water spaces of the boiler, a steam and Water separator betweenthe upper end of one of said downcomer pipes and the upper header, and`a connection between said separator and the steam spaces of the boiler.

9. In a boiler, a furnace, an upper header and a lower header, aconnection from said boiler to said lower header, a row of furnace walltubes connecting said upper and lower headers and delivering a mixtureof steam and water to said upper header, means to cause the waterdelivered to said upper header to be divided into two parts, said meanscompri/sing a recirculator be- `tween said headers to,return a portionof said water to said lower header, and also comprising a connectionfrom said upper header to a higher point in said boiler than the placewhere said lower header is connected to the boiler for returning saidsteam and the remainder of said water to said boiler, the point of saidconnection to the boiler being above the aforesaid upper header adistance at least half the distance between said headers.

10. In a boiler, a furnace, an upper header and a lower header, aconnection from said boiler to said lower header, a row of furnacewall-tubes connecting said upper and lower headers and delivering amixture of steam and water to said upper header, means to cause thewater delivered to said upper header to be divided into parts, saidmeans comprising a recirculator between said headers to return a portionof said water to said lower header, and also comprising a connectionfrom said upper header to a higher point in said boiler than the placewhere said lower header is connected to the boiler for returning saidsteam and the remainder of said water to said boiler, said connectionfrom the upper header to the boiler having a cross-sectional area lessthan that of said row of furnace wall tubes.

l1. In a boiler, a furnace, upper and lower headers, a connection fromsaid boiler to said lower header, a row of furnace wall tubes connectingsaid upper and lower headers and dclivering a mixture of steam and waterto said upper header, means to cause the water delivered to said upperheader to be divided into two parts, said means comprising arecirculator between said headers toreturn a portion of said water tosaid lower header, and also comprising ail a connection from said upperheader to a higher point in said boiler than the place where said lowerheader is connected to the boiler for returning said steam and theremainder of said water to said boiler, said connection from the upperheader to the boiler having a cross sectional area less than that ofsaid recirculator.

12. In a boiler, a furnace, an upperand lower header, a row of furnacewall tubes connecting said upper and lower headers and delivering amixture of steam and water to said upper header,

a connection from said boiler to said furnace wall tube arrangement,means to cause the water delivered to said upper header to be dividedinto two parts, said means comprising a recirculator between saidheaders to return a portion of said water to said lower header, and alsocomprising a connection from said upper header to a higher point in saidboiler than the place where said lower header is connected to the boilerfor returning said steam and the remainder of said water to said boiler,the point of said connection to the boiler being above the aforesaidupper header a distance at least half the distance between said headers.

13. In combination, a vapor generator including a vapor and liquidseparator having a maintween the compartments returning the remainder ofthe liquid to the lower compartment, and a supply connection constantlyreplacing with 1iq`- uid any liquid and vapor removed from the uppercompartment.

14. In combination, a vapor generator including a vapor and liquidseparator having a maintained liquid level, furnace walls enclosing acombustion chamber heating said generator, means for firing saidcombustion chamber with finely divided fuel, furnace wall protectingtubes spaced along at least one of the walls and subjected to radiantheat for a major portion of their length, compartments, one connectingthe upper adjacent ends of said tubes and the other the lower adjacentends, both submerged beneath the liquid level of the separator, aconnection from the upper compartment to the generator to take away partof the liquid caused to move upwardly of the tubes by heat ofcombustion, a connection between the compartments returning theremainder of the liquid to the lower compartment, and a supplyconnection constantly replacing with liquid any liquid and vapor removedfrom the upper compartment.

15. In combination, avapor generator including a vapor and liquidseparator having a maintained liquid level, furnace walls enclosing` acombustion chamber heating said generator, means for ring saidcombustion chamber with nely divided fuel, furnace wall protecting tubesspaced along at least one of the walls and subjected to the furnace heatin the flame zone, compartments, one connecting the upper adjacent endsof said tubes and the otherthe lower adjacent ends, both submergedbeneath the liquid level of the separater, a connection from the uppercompartment to the generator to take away part of the liquid caused tomove upwardly of the tubes by heat of combustion, a connection betweenthe compart- `ments returning the remainder of the liquid to the lowercompartment, and a supply connection constantly replacing with liquidany liquid and vapor removed from the upper compartment.

16. In a boiler furnace, a bank of vertically disposed furnace wallcooling tubes subjected to the heat of the furnace, an upper and a lowerhorizontal header to which the ends of said tubes are connected, aconnection between said headers outside of said furnace, a connectionbetween the lowerheader and the boiler and a connection between theupper header and a higher point of the boiler, said last namedconnection being no larger in effective area than that of saidconnection between the lower header and the boiler.

1'7. In a steam boiler and its setting, a furnace wall, a steam andwater drum, a circulatory system for said boiler including tubes andwater chambers connected to said drum, upper and lower chambers locatedbelow said first-named chambers, tubes connecting said last-named waterchambers and located adjacent to and cooling said furnace wall, othertubes connecting said last-named water chambers and located at the rearof said wall whereby a circulation may take place through the tubesconnecting said lastnamed water chambers, a connection between saidupper chamber and said steam and Water drum, and connections betweensaid circulatory system and said lower water chamber.

JAMES C. HOBBS.

